1. Field of the Invention
The present invention relates to electrical connectors and more particularly to multi-outlet adapter for distributing identical signal so as to increase the utilization of existing receptacles for plug-in modular plugs.
2. Description of the Prior Art
RJ modular connectors have been widely used in telecommunication systems ever since they were first created and adopted by the industry. An RJ45 modular connector, which includes a total of eight terminals, and RJ11 modular connectors, which can include two, four, or six terminals, have been widely used in the network systems and telephone equipment, respectively.
Among hundreds of different applications of the RJ45, there are at least eight different patterns in selecting terminals as differential pair, i.e. T568A, T568B, USOC 4-pair, USOC 1-, 2- or 3-pair, 10BASE-T (802.3), Token Ring (802.5), 3-pair (MMJ), and TP-PMD (X3T9.5) and ATM. In each implementation, two terminals are selected as a pair in which some are close to each other, while some are apart from each other. Each pattern has its own uniqueness, while each also carries a coupling issue that needs to be solved.
Among those patterns, T568A and T568B are widely used and in T568A, terminals 1,2 configure 3rd pair, terminals 3,6 configure 2nd pair, terminals 4,5 configure 1st pair, while terminals 7,8 configure 4th pair. In T568B, terminals 1,2 configure 2nd pair, terminals 3,6 configure 3rd pair, terminals 4,5 configure 1st pair, while terminals 7,8 configure 4th pair.
However, in the TP-PMD and ATM application, as best seen in http://cctr.umkc.edu/ref/ele/rj45.html only 1st, 2nd, 7th and 8th terminals are used, while 3rd, 4th, 5th, and 6th terminal are left unused. If an existing RJ45 is used in T568A and T568B applications, a total of eight terminals are used, while in TP-PMD and ATM application, 50% of the terminals are left unused.
U.S. Pat. No. 4,444,451 issued to Myers on Apr. 24, 1984 discloses a modular plug-dual modular jack adapter.
U.S. Pat. No. 4,799,901 issued to Pirc on Jan. 24, 1989 discloses a modular adapter comprising upper and lower housings, first and second connector subassemblies, a transient voltage suppression module and a grounding shell. The first and second connector subassemblies include, respectively, first and second dielectric support members and eight first and second terminals. The transient voltage suppression module includes a circuit board having a plurality of electrical circuit components mounted thereon, and grounding strap having grounding legs extending through apertures in the circuit board. However, the structure of the Pirc adapter requires numerous components and procedures, it is overly complicated such that production cost is increased. Furthermore, in Pirc adapter, signals are transmitted form the first terminals to the second terminals, while 50% of the terminals are left unused.
Hence, an improved adapter suitable for telecommunication is required to overcome the disadvantages of the prior art.